Organic-light emitting device and method of manufacturing the same

Abstract

An organic light-emitting device including: an anode; a hole charging layer (HCL) comprising an oxide semiconductor and formed on the anode; at least one organic layer formed on the HCL; and a cathode formed on the organic layer. The HCL may be an oxide semiconductor including indium (In), gallium (Ga), and zinc (Zn), or an oxide semiconductor including In, Zn, and hafnium (Hf).

What is claimed is: 
     
       1. An organic light-emitting device comprising:
 an anode; 
 a hole charging layer (HCL) comprising an oxide semiconductor on the anode; 
 at least one organic layer formed on the HCL; 
 a cathode formed on the organic layer; and 
 wherein the HCL is an oxide semiconductor comprising indium (In), gallium (Ga), and zinc (Zn) or an oxide semiconductor comprising In, Zn, and hafnium (Hf). 
 
     
     
       2. The organic light-emitting device of  claim 1 , wherein in the oxide semiconductor comprising In, Ga and Zn, the In, Ga, and Zn are from about 30 to about 50%, from about 30 to about 50%, and from about 10 to about 35%, respectively. 
     
     
       3. The organic light-emitting device of  claim 1 , wherein in the oxide semiconductor comprising In, Zn and Hf, the In, Zn, and Hf are from about 35 to about 55%, from about 35 to about 55%, and from about 5 to about 15%, respectively. 
     
     
       4. The organic light-emitting device of  claim 1 , wherein the band gap energy of the oxide semiconductor is from about 3 to about 3.5 eV, and the valence band energy of the oxide semiconductor is between a work function of the anode and an HOMO energy of the organic layer contacting the oxide semiconductor layer. 
     
     
       5. The organic light-emitting device of  claim 4 , wherein the energy state of the oxide semiconductor comprises a band tail state energy level and a deep state energy level. 
     
     
       6. The organic light-emitting device of  claim 1 , wherein the organic layer comprises an emission layer. 
     
     
       7. The organic light-emitting device of  claim 6 , wherein the oxide semiconductor layer and the emission layer share a light-emitting region. 
     
     
       8. The organic light-emitting device of  claim 7 , wherein the organic light-emitting device emits light from about 400 nm to about 700 nm. 
     
     
       9. The organic light-emitting device of  claim 6 , wherein the organic layer further comprises at least one layer selected from the group consisting of an HIL and an HTL, between the oxide semiconductor layer and the EML. 
     
     
       10. The organic light-emitting device of  claim 6  or  7 , further comprising at least one selected from the group consisting of an ETL and an EIL, between the EML and the cathode. 
     
     
       11. The organic light-emitting device of  claim 1 , wherein the anode comprises indium tin oxide (ITO) or indium zinc oxide (IZO). 
     
     
       12. The organic light-emitting device of  claim 1 , wherein the organic light-emitting device emits blue, red, or green light. 
     
     
       13. The organic light-emitting device of  claim 1 , further comprising:
 a substrate; 
 a thin film transistor comprising a gate electrode formed on the substrate, a gate insulating layer formed on the gate electrode and the substrate, an active layer facing the gate electrode and formed on the gate insulating layer, and source and drain electrodes that are electrically connected to the active layer; and 
 an insulating layer, 
 wherein the anode contacts the source and drain electrodes by passing through the insulating layer. 
 
     
     
       14. A method of manufacturing an organic light-emitting device, the method comprising:
 forming an anode; 
 forming a hole charging layer (HCL) comprising an oxide semiconductor on the anode; 
 forming at least one organic layer on the HCL; and 
 forming a cathode on the organic layer; 
 wherein the HCL is an oxide semiconductor comprising indium (In), gallium (Ga), and zinc (Zn) or an oxide semiconductor comprising In, Zn, and hafnium (Hf). 
 
     
     
       15. The method of  claim 14 , wherein in the oxide semiconductor comprising In, Ga and Zn, the In, Ga, and Zn contents are from about 30 to about 50%, from about 30 to about 50%, and from about 10 to about 35%, respectively. 
     
     
       16. The method of  claim 14 , wherein in the oxide semiconductor comprising In, Ga and Zn, the In, Ga and Zn contents are from about 20 to about 40%, from about 20 to about 40%, and from about 20 to about 40%, respectively. 
     
     
       17. The method of  claim 14 , wherein in the oxide semiconductor comprising In, Zn and Hf, the In, Zn, and Hf contents are from about 35 to about 55%, from about 35 to about 55%, and from about 5 to about 15%. 
     
     
       18. The method of  claim 14 , wherein the band gap energy of the oxide semiconductor is from about 3 to about 3.5 eV, and the valence band energy of the oxide semiconductor is between a work function of the anode and a highest occupied molecular orbital (HOMO) energy of the organic layer contacting the oxide semiconductor layer.